If you're purchasing a new PC, most versions of Windows 10 will come pre-installed with unnecessary software, or bloatware, that most people don't need or want. Getting a new PC from an OEM organization comes pre-loaded with even more bloatware.
You can manually delete bloatware yourself, but Leo recommends running PowerShell to rapidly delete the unnecessary software. Alternatively if you're not comfortable using PowerShell, you can run a script that will clean up Windows 10 and get rid of a lot of bloatware on it. Jess Fraz's script is a great example.